Zusammenfassung / Abstract

Hydrogels are macromolecular structures of cross-linked hydrophilic polymers capable of storing immense amounts of water and other hydrophilic solvents. As smart hydrogels, special gel systems show a very intense response to external stimuli: Sudden transitions between swollen and shrunken states may occur. The storage capability and the absorption sensitivity towards certain substances depend strongly on external conditions like temperature or concentrations of co-solvents, non-ionic solutes or ions.

For the thermodynamic description of such behaviour, the PC-SAFT equation of state can be used with an additional contribution to the Helmholtz energy, considering elastic forces within a polymer network. Regarding explicitly the elastic pressure induced by the gel swelling, the thermodynamic behaviour of hydrogels can be calculated and predicted.